Switchboard



Patented Mar. 16, 1948 2,438,025 .SWITCHBOARD vl' iilliam Taliaierro,

Westinghouse Electr burgh, -Pa., ,9. corpora Edgewood, Pa, ic Corporation, tion of Pennsylvania assignor to East Pitts- Application February 10, 1944, Serial No. 521,869 Claims. (Cl. 175-407) 1 My invention-relates,generaily, to switchboards and, moreparticularly, to switchboard structures "for supporting automatic circuit breakers similar-switching apparatus.

In-the construction of'switchboards for use on it can withstand severe shocks. 'l-Ieretofore, it has been customary'to'mount-circuit breakers of certain types on heavy slabs of an impregnated fabric materialreinforced by steel angles. This construction isheavy in order to resist shock from explosion and is expensive. It also requires large amount of the impregnated material which at the present'time is scarce and dificult'to secure. Furthermore, it is inflammable and, therefore, constitutes a fire hazard.

An object of my invention, generally stated, is toprovidean improved means-for mounting electrical apparatus, such as circuit breakers, on switchboard structures.

Amorespecific object of my invention is to reduce the weight and cost of a mounting struc- 'ture for switchgear apparatus.

Another object of my invention is to provide a mounting structure of the character described which shall be capable of withstanding severe shocks.

A further object of my invention is to reduce the fire hazard of a mounting structure for switchgear apparatus.

Other objects of my invention will be explained fully hereinafter or will be apparent to those skilled in the art.

'In accordance with one embodiment of my in- 'vention, a plurality of circuit breaker units are mounted on a steel pan which is secured to a switchboard frame. The'bi'ealier terminal studs extend through holes in the pan and are insulated therefrom by insulating blocks and tubes which surround the studs. If desired, barriers may be secured to the pan to isolate-the breaker units.

Fig. 3 is an enlarged view, in section, taken along the line IIIIII of Fig. 1; and

Fig. 4 is a view, similar to Fig. '3, showing a modification of the mounting structure.

Referring :to the drawing, and particularly to "Figs. land 2,"the structure shown therein comtype having between the pan 23 and 56 which are threaded insertsdlznay be provided unit is removedfrorn 'When the bolts 36 are prises a plurality of enclosed switch units iii, a switchboard frame which may be of the usual and l disposed at the front and the rear thereof, respectively, and'horizontal members 53, it, i5, it, i? and it for'tying the upright members together, a front panel 53 which may be removably secured to the frame by brackets 2i a pair of channel members 22 for supporting the frame. Since the framework may be of the usual construction, it is believed to be unnecessary to describe it further at the present time.

In order to'support the switch units it! in the switchboard frame, a metal pan 23 may be re movably secured to theupright members It by a plurality of bolts i i. If desired, the pan may be welded to the switchboard frame. As shown, horizontally and vertically disposedbarriers 25 may be welded to the pan 23 between the switch units it to reinforce the pan and isolate each switch unit from the other units.

As shown more clearly in Fig. 3, the pan 23 provided with openings so for receiving terminal studs 2? for the switch units. Each stud 2? is provided with a shoulder 28 near one end and a nut 29 which is threaded on to the other end of the stud. The usual electrical connections (not shown) for the switch units may be secured to the portions of the studs which extend beyond the nuts 29.

As shown in Figs. 1 and 3, blocks 3 l, composed of insulating material, is provided for each switch unit. Ehe blocks disposed between the shoulders .28 of the studs 23 and the pan 23. An insulating sleeve sur rounds each stud El and extends through the opening '25. Another insulating sleeve 33 surrounds the sleeve t on each stud and is disposed the nut 29. Thus, it will be seen that whenthe nut is tightened against thesleeve 33, thestudis securely held in the pan 23 and is completely insulated from the pan.

Each block (it is secured to the pan 23 by bolts which extend through the pan 23 threaded into metal inserts 35 disposed in the blockli l. The switch unit 1 is supported by bolts 'threadedinto the end or" the inserts .35 opposite the bolts i i. If desires,

in the housing .forthe switch unit it to prevent the bolts 38 from falling out of the housing when the switch the switchboard structure. first inserted into the locus ing 18, they may be threaded through the inserts 3.7 andinto the inserts in the spacing blocks 13 l.

Asshcwn in 3,'the switch unit it may be electrically connected to the studs 27 by contact members or" the plug-in type. Each contact member comprises a stud 38, which is preferably pair of spacing molded into the housing for the switch unit, and a plurality of contact fingers 39 which are retained on the stud 38 by a garter spring 4| and are disposed to engage the end of the stud 2'5 when the switch unit is mounted in position on the spacing block 3|. A garter spring 42 biases the fingers 39 against the stud 21.

In this manner, the switch unit it! is mechanically secured to the pan 23 by the bolts 36 and electrically connected to the studs 21 by the plug in contact members. A switch unit may be removed from in front of the switchboard structure by removing bolts 36 from 3!. It is not connections on the rear ends of order to remove a switch unit.

In the structure shown in Fig. 4, in which like parts are designated by the same reference characters as in Fig. 3, the switch unit in is supported by the terminal studs 2?. An insulating sleeve 433 is provided for each stud 21 in place of the insulating block 3| which is provided for each group of three studs in the structure shown in Fig. 3. The sleeves 43 surround the sleeves 32 and are disposed between the shoulder 28 on each stud and the pan 23. An insulating washer it may be disposed between the end of the sleeve 63 and shoulder 28 for additional protection if desired. Thus, when the nut 29 is drawn against the sleeve 33, the stud 2! is secured in position in the pan 23 and is completely insulated from the pan.

The switch unit in is both electrically and mechanically connected to the stud 21 by means of a pair of stud bolts 55 which are threaded into the shoulder 28 of the terminal stud 21. A nut 46 may be utilized on each bolt 45 to draw the housing for the switch unit ill against the shoulder 28, thereby securing the switch unto the terminal stud. The necessary electrical connections for the switch unit it] may be made to the studs 45 inside of the housing in the usual manner.

From the foregoing description, it is apparent that I have provided for mounting a plurality of switch units in a switchboard structure in a manner which is capable of withstanding severe shocks and which requires a relatively small amount of insulating material for satisfactorily insulating the switch units from the metallic members of the structure. Furthermore, the housings for the switch units are separated from the bus bars at the rear of the structure by the steel mounting pan, thereby reducing the danger of the switch units being set on fire by arcs drawn between the power conductors at the rear of the structure. Each switch unitmay be isolated in a cell formed by barriers in the mounting pan as a further protection against communication of fire. Both the weight and the cost of the mounting structure are reduced as compared with prior structures requiring large amounts of heavy insulating material.

Since numerous changes may be made in the above described construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanyin drawing, shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a switchboard structure having a supporting framework, a front panel removably attached to the framework, and a metal pan secured to the framework and spaced from the panel for supporting a plurality of apparatus units, in combithe inserts 35 in the spacing blocks necessary to disturb the electrical the studs 21 in the panel l9 and unscrewing the nation, horizontal and vertical metal barriers extending between the panel and the pan and secured to said pan and disposed between the apparatus units to isolate each unit from the other units and reinforce the pan, said pan having a plurality of openings therein, terminal studs for the apparatus units disposed in said openings, insulating means for spacing the studs and the apparatus units from said pan, means for securing the studs to the pan, and means for connecting the apparatus units to the studs.

'2. In a switchboard structure having a supporting framework, a front panel removably attached to the framework, and a metal pan secured to the framework and spaced from the panel for supporting a plurality of apparatus units, in combination, horizontal and vertical metal barriers extending between the panel and the pan and secured to said pan and disposed between the apparatus units to isolate each unit from the other units and reinforce the pan, said pan having a plurality of openings therein, terminal studs for the apparatus units disposed in said openings, an insulating sleeve surrounding each stud, insulating means surrounding said sleeves for spacing the apparatus units from the pan, means for securing the studs to the pan, and means for connecting the apparatus units to the studs.

3. In a switchboard structure having a supporting framework, 2. front panel removably attached to the framework, and a metal pan secured to the framework and spaced from the panel for supporting a plurality of apparatus units, in combination, horizontal and vertical metal barriers extending between the panel and the pan and secured to said pan and disposed between the 'apparatus units to isolate each unit from the 01; e1 units and reinforce the pan, said pan having a plurality of openings therein, terminal studs for the apparatus units disposed in said openings, each stud having a shoulder near one end and a removable nut near the other end, an insulating sleeve surrounding each stud, spacing means surrounding said sleeves and disposed between said shoulders and the pan, additional spacing means disposed on said sleeves between the pan and said nuts, and means for connecting the apparatus units to the studs.

4. In a switchboard structure having a supporting framework, a front panel removably attached to the framework, and a metal pan secured to the framework and spaced from the panel for supporting a plurality of apparatus units, in combination, horizontal and vertical metal barriers extending between the panel and the pan and secured to said pan and disposed between the apparatus units to isolate each unit from the other units and reinforce the pan, said pan having a plurality of openings therein, terminal studs for the apparatus units disposed in said openings, an insulating sleeve surrounding each stud, insulating means surrounding said sleeves for spacing the apparatus units from the pan, means for removably securing the units to the pan, means for securing the studs to the pan, and means disposed in said units for removably engaging the studs.

5. In a switchboard structure having a supporting framework, 2. front panel removably attached to the framework, and a metal pan secured to the framework and spaced from the panel for supporting a plurality of apparatus units, in combination, horizontal and vertical metal barriers extending between the paneland the pan and secured to said pan and disposed be- WILLIAM R. TALIAFERRO.

REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Lee Apr. 30, 1912 Ziegler Oct. 29, 1912 Hooley Dec. 29, 1931 Weber Mar. 7, 1933 Graves Apr. 17, 1934 Hammerly May 15, 1934 Bucher May 19, 1936 Randall Aug, 11, 1936 Koehler July 6, 1937 Freese May 7, 1940 Paulson May 21, 1940 West Oct. 5, 1943 

